Mercury derivatives of hydroxybenzoic acids



Patented Feb. 3, 1925.

UNITED STATES 1,525,078 PATENT OFFICE.

WALTER KROPP, OF ELBERFELD, GERMANY, ASSIGNOR T0 FARBENFABRIKEN VORM.

FRIEDR. BAYER AND (10., OF LEVERKUSEN, NEAR COLOGNE-ON-THE-RHINE, GER-MANY.

MERCURY DERIVATIVES OF HYDROXYBENZOIC ACIDS.

2N0 Drawing.

To all whom it may concern:

Be it known that I, WALTER Knorr, a citizen of Germany, residing atElberfeld, in the State of Prussia, Germany, have invented new anduseful Improvements in Mercury Derivatives of Hydroxybenzoic Acids, ofwhich the following is a specification.

My invention relates to the preparation of the hitherto unknown mercurycompounds of substituted hydroxy acids of the benzene series, e. ofpara-benzylhydroxybenzoic acid, having the following general formulaR-O-O R stands for an aromatic radicle, such as phenyl, tolyl; R standsfor an aryl and aralkyl.

The new products can be obtained by treating the said substitutedhydroxybenzoic acids with mercuric oxide or salts of mercury.

The new products are whitish compounds which are generally soluble withdifliculty in water, alcohol and ether, soluble in dilute solutions ofsodium carbonate, insoluble in dilute mineral acids, e. g. the acid ofthe stomach. Owing to these properties they go unaltered through thestomach and show their therapeutic action only in the intestines. Theyhave provedto be valuable antisyphilitics characterized by a mild actionand the fact that they are non-irritant and not corrosive renders themhighly valuable for internal application. They can be taken per os.

In order to illustrate my new process more fully the following exampleis given 114 parts by weight of para-benzylhydroxybenzoic acid havingmost probably the following formula:

are triturated together with 155 parts by weight of acetate of mercuryand the nnx- Application filed March 7, 1924. Serial No. 697,674.

ture is heated in an oilbath to 14;0-150 C. until a testgortion issoluble in dilute caustic soda lye. ubsequently the melt is treated withhot alcohol and the precipitate is dissolved in dilute caustic sodasolution and the resulting solution is filtered. Thehydroxy-mercuri-para-benzyl hydroxybenzoic acid anhydride isprecipitated from the alkaline solution by means of CO It is a whitishpowder which decomposes on heating. It is soluble with difiicult-y inwater, alcohol and ether. It contains about 47 per cent of mercury. Itmost probably has the formula corn-0.11.

o.mo=o

Hg-O

Other substituted monoaryl-v or monoaralkyl-hydroxybenzoic acids may beused e. g. ortho-benzylhydroxybenzoic acid:

or ortho-phenyl-hydroxybenzoic acid:

OOOH

OOOH

anhydride being a whitish powder having most probably the formula:

with diificulty in water, alcohol and ether,

containing about 47 per cent mercury and 10 being a valuableantisyphilitic which can be taken per os, substantially asv described.

In testimony whereof I have hereunto set my hand.

WALTER KROPP.

